Thermal power plants use 4x more water than all US residents, solar PV doesn't need a drop

Water conservation: Another overlooked benefit of solar power!

As you can see in the satellite photos above, California is experiencing a massive drought over most of the state. The most visible aspect from space is the snow cover (or lack thereof) over the Sierra Nevada mountain range, but on the ground, things are even more obvious; the state is dry, dry, dry... Reservoirs are empty, ranchers can't feed their herds, farmers can't grow their crops. It hasn't been that bad in decades...

So now is a good time to remind ourselves of just how much water is used by thermal power plants, which boil water to create steam. The Union of Concerned Scientists released a report on this a few years ago, and what it says is striking.

Thermal power plants in the U.S. used as much water as farms did in 2005, and more than four times as much as all U.S. residents. Every single day in 2008, these power plants withdrew 60 to 170 billion gallons of freshwater from rivers, lakes, streams and aquifers, and consumed 2.8 to 5.9 billion gallons of that water. This is particularly bad in the southwest because a lot of the water used by power plants came from underground aquifers that don't always replenish quickly.

Withdrawal is the total amount of water a power plant takes in from a source such as a river, lake, or aquifer, some of which is returned. Consumption is the amount lost to evaporation during the cooling process. Withdrawal is important for several reasons. Water intake systems can trap fish and other aquatic wildlife. Water withdrawn for cooling but not consumed returns to the environment at a higher temperature, potentially harming fish and other wildlife. And when power plants tap groundwater for cooling, they can deplete aquifers critical for meeting many different needs. Consumption is important because it too reduces the amount of water available for other uses, including sustaining ecosystems. (source)

But solar? It doesn't stress our water resources and exacerbate droughts. In fact, it produces more power during very hot and sunny periods. SolarCity estimates that through the California Solar Initiative, SolarCity and other companies have deployed enough solar to conserve 684 million gallons a year for the state. Not bad!

Thermal power plants use 4x more water than all US residents, solar PV doesn't need a drop

As you can see in the satellite photos above, California is experiencing a massive drought over most of the state. The most visible aspect from space is the snow cover (or lack thereof) over the Sierra Nevada mountain range